The invention relates to a hearing aid device which can be worn in the ear or a hearing aid device with a otoplastic which can be worn in the ear, which comprises at least a first microphone for picking up a first acoustic signal and emitting a first electrical microphone signal, a signal processing unit, a first earphone for emitting a first earphone signal and a ventilation channel, which is used for ventilating the volume of the auditory canal that is enclosed by the hearing aid device when it is being worn or by the otoplastic when it is being worn.
In the case of a hearing aid device which can be worn in the ear or a hearing aid device with a otoplastic which can be worn in the ear, the housing of the hearing aid device or the otoplastic closes the external auditory canal of an ear with a largely soundproof effect. The housing of the hearing aid device which can be worn in the ear or the otoplastic which can be worn in the ear usually has a ventilation channel passing through it, which serves for ventilating and venting the closed portion of the external auditory canal.
The cross-sectional surface area of this ventilation channel must generally be kept relatively small in order largely to avoid acoustic interference signals which pass through the ventilation channel, thereby bypassing the electrical signal processing by the hearing aid device. However, a large diameter has the advantage of better ventilation and a smaller occlusion effect. Nevertheless, a significant low-frequency direct sound component passes through a ventilation channel with a large cross section into the volume of the auditory canal enclosed by the hearing aid device or the otoplastic. The larger the cross section of the ventilation channel, the higher the limiting frequency below which a notable direct sound enters the auditory canal.
The ventilation channel represents an acoustic bypass with respect to the electrical signal path through the hearing aid device. Interference signals, which usually have a large low-frequency component, can therefore no longer be damped by the electrical signal processing in the hearing aid device. To avoid this effect, the cross section of the ventilation channel must be made as small as possible. As a result, however, adequate ventilation and venting of the enclosed volume of the auditory canal often cannot be ensured any longer.
German patent document DE 40 10 372 A1 discloses a hearing device with an earpiece that can be inserted into the external auditory canal of an ear and has a ventilation channel, in which device an acoustic input signal is picked up by a first microphone and converted into an electrical microphone signal, subjected to signal processing in a signal processing unit and converted back into an acoustic signal and emitted into the auditory canal of the person wearing the hearing device by a first earphone. In the case of the known hearing device, in the ventilation channel there is a second microphone and a second earphone, sound waves generated by the first earphone being picked up by the second microphone, phase-shifted and emitted again by the second earphone, so that sound waves of the first earphone penetrating through the ventilation channel from the enclosed volume of the auditory canal to the outside are largely suppressed.